1. Field of the Invention
The present invention relates to a method of packaging a multi-channel optical receiver module and a package of the same.
2. Discussion of Related Art
A method of transmitting optical signals having wavelengths different from each other to one optical fiber by performing a wavelength division multiplexing (WDM) on the optical signals is being used as technology for transmitting high-quality and large-capacity data traffic. The WDM method is an optical multiplexing method of transmitting various wavelength bands simultaneously, can transmit a variety of transmission information through one optical fiber, and has a transmission capacity which is equal to or more than 40 Gbps.
Meanwhile, the WDM method may be divided into a coarse WDM (CWDM) and a dense WDM (DWDM). In the case of the CWDM has a large wavelength interval of tens of nanometers (nm), has a low cost as the number of usable wavelengths is 4 to 8, and is mainly used for an access network. The DWDM has a wavelength interval of several nm and is mainly used for a medium and long-range transmission.
While the WDM method has been mainly used for a backbone network, the WDM method has been also applied to an access loop network and an Ethernet network.
The CWDM method having four wavelengths is being used as a standard for the Ethernet, and various methods for implementing a four-wavelength transmitter optical sub-assembly (TOSA) and a four-wavelength receiver optical sub-assembly (ROSA) absolutely needed for the CWDM method are being proposed. In this case, the TOSA performs a four-channel electrophotic conversion function and a wavelength multiplexing function, and the ROSA performs a wavelength demultiplexing function and a four-channel photoelectric conversion function.
In an optical transceiver for the Ethernet network, miniaturization and low power consumption of the optical transceiver are needed for lower power consumption and integration of a data center, and optical alignment, packaging, reliability of the optical module embedded in the optical transceiver are very important.
However, conventional arts having various structures are difficult to miniaturize due to a characteristic of their structures and have a problem of a great loss according to an optical alignment. Further, the conventional arts have a problem in that it is difficult to package, and thus mass production is very difficult.
Regarding the conventional arts, United States Patent (USP) Publication No. 2006-0088255 (Title: multi-wavelength optical transceiver subassembly module) discloses technology in which only an optical signal having a corresponding wavelength is transmitted by thin film filters and the optical signals having the remaining wavelengths are reflected when optical signals having various wavelengths are incident to the thin film filters aligned in a pentagon shape through a receptacle.
However, the conventional art has a problem in that it is difficult to miniaturize due to a characteristic of its structure. Further, the conventional art has a problem in that a great loss occurs according to an optical alignment, and it is difficult to package, and thus mass production is difficult.